{"id":"DEBIAN-CVE-2026-53583","details":"libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, verify_server_cert in src/libgit2/streams/openssl.c uses an inverted !!memcmp result in the GEN_IPADD branch when comparing an IP-literal host with a certificate IP SubjectAltName. OpenSSL builds reject matching IP addresses and accept mismatched IP addresses, allowing a network attacker with a CA-trusted certificate containing any IP SubjectAltName to intercept libgit2 connections to IP-literal HTTPS URLs. DNS SubjectAltName validation and non-OpenSSL TLS backends are not affected. This issue is fixed in versions 1.8.6 and 1.9.5.","modified":"2026-09-10T08:47:27.543310710Z","published":"2026-08-20T19:16:54.500Z","upstream":["CVE-2026-53583"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-53583"}],"affected":[{"package":{"name":"libgit2","ecosystem":"Debian:12","purl":"pkg:deb/debian/libgit2?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.1+ds-1","1.5.1+ds-1+deb12u1","1.6.4+ds-1","1.7.1+ds-1","1.7.1+ds-2","1.7.2+ds-1","1.8.1+ds-1","1.8.1+ds-2","1.8.2~rc1+ds-1","1.8.2~rc1+ds-2","1.8.2~rc1+ds2-1","1.8.4+ds-1","1.8.4+ds-2","1.8.4+ds-3","1.8.4+ds-3~bpo12+1","1.8.4+ds-3~bpo12+1~bin","1.9.0+ds-1","1.9.0+ds-2","1.9.1+ds-1","1.9.2+ds-1","1.9.2+ds-2","1.9.2+ds-3","1.9.2+ds-4","1.9.2+ds-5","1.9.2+ds-6","1.9.2+ds-7","1.9.2+ds-8","1.9.2+ds-9","1.9.3+ds-1","1.9.4+ds-1","1.9.6+ds-1","1.9.7+ds-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53583.json"}},{"package":{"name":"libgit2","ecosystem":"Debian:13","purl":"pkg:deb/debian/libgit2?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.0+ds-2+deb13u1"}]}],"versions":["1.9.0+ds-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53583.json"}},{"package":{"name":"libgit2","ecosystem":"Debian:14","purl":"pkg:deb/debian/libgit2?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.6+ds-1"}]}],"versions":["1.9.0+ds-2","1.9.1+ds-1","1.9.2+ds-1","1.9.2+ds-2","1.9.2+ds-3","1.9.2+ds-4","1.9.2+ds-5","1.9.2+ds-6","1.9.2+ds-7","1.9.2+ds-8","1.9.2+ds-9","1.9.3+ds-1","1.9.4+ds-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53583.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"}]}